1. Field of the Invention
This invention relates to a collapsible/expandable shipping rack having an erected configuration and a storage configuration. The end walls are expandable both horizontally and vertically to alter the size of the rack.
2. Prior Art
In modern manufacturing, it is common practice to assemble completed units at a single location from various parts and components which are shipped to the assembly location from other locations. The parts and components are normally fabricated in facilities remote from the assembly location and shipped to the assembly location in containers. Two problems have arisen in connection with prior art containers. One type of container which has been in common use in the past is the throw-away container. Such containers are fabricated of materials such as cardboard and low grade wood. Throw-away containers have presented a serious disposal problem at assembly plants. Additionally, such throw-away containers are not available in units of sufficient strength to ship heavy parts and components.
Reusable racks fabricated of heavy duty steel have been in common use in the past. Such racks are strong in construction and are capable of retaining heavy parts and components. These racks have had the disadvantage of being expensive to transport empty back from an assembly location to the location of the origin of parts and components for refilling and reshipment.
Collapsible racks have been suggested to reduce the volume of empty racks for reshipment. However, collapsible racks fabricated of steel have still suffered from the disadvantage of being quite heavy which involves expensive reshipment costs. Also, such collapsible racks have suffered from a low return ratio. The return ratio is the ratio between the volume of a fully erected container and a collapsed and stored container. Further, such racks made of steel have suffered a rust problem. Prior art racks have also been of a fixed size thus requiring an extensive inventory of rack sizes to suit the various differently sized parts and components.
In accordance with the present invention a collapsible rack is provided which has a relatively high return ratio, the return ratio being approximately 3:1. Further, the rack is fabricated of a combination of plastic and light weight aluminum materials thus reducing the weight substantially, for example, illustratively from over 1000 pounds for a dunnage rack 106 inches long by 48 inches wide and 41 inches high. A similar rack made in accordance with the present invention has exterior dimensions of 96 inches by 51 inches by 51 inches and weighs approximately 360 pounds. Furthermore, the end walls of the rack are expandable both vertically and horizontally to permit variation in the interior rack size thus facilitating loading the rack with variously sized parts and components. For example, the rack may be loaded with automotive gas tanks which vary considerably in size from those used on smaller vehicles to those used on larger vehicles. The rack size can be tailored to the particular size of the gas tanks being shipped.